PROJECT SUMMARY/ABSTRACT The Tisch Cancer Institute (TCI) Microscopy Shared Resource Facility (MSRF) provides TCI members access to equipment, training, expert consultation, and collaborative opportunities across a full-range of light and electron microscopy applications, including: confocal, multiphoton, super-resolution, in vivo imaging, light sheet, widefield, and transmission electron microscopy (EM). Three high-end workstations equipped with state-of-the- art software accompanied by a local server and high-speed connectivity permit a wide range of image analysis and quantification strategies. Five full time scientists staff the MSRF during regular hours and provide real-time assistance to both novice and experienced users. All of the MSRF scientists can be tapped for implementing advanced approaches. Each holds a PhD or was otherwise trained intensively in a field having particular relevance to their imaging specialty such as super-resolution microscopy or computer engineering. In particular, the EM specialist is a leader in the field and has published over ninety papers covering everything from correlative light-EM (CLEM) to traditional EM techniques, and the scientific advisor is also a TCI member who is expert in intravital imaging approaches and works collaboratively with novice TCI users needing to apply this strategy to cancer-related questions. The MSRF also sponsors monthly seminars featuring scientists using microscopy or vendors developing relevant new technology and its scientists co-direct an annual hands-on microscopy course for graduate school trainees and host workshops throughout the year. The capabilities of the microscope systems together with the skills and training of the team are crucial for supporting TCI studies that include multichannel immunofluorescence for tumor diagnostics, localization of cell signaling and growth regulatory molecules, tumor cell migration and invasion, and cell biological mechanisms of metastasis and dormancy.